Measurement of electric power is performed by means of inclusion in an electrical circuit of a wattmeter. Determination of power an indirect way is also possible what measurements of current and tension in a chain are made for.
It is required to you
- wattmeter or multimeter, screw-driver, wires, knife
Instruction
1. Preparatory operations. Cut off power an electrical circuit by switching off of the entrance automatic machine or the switch. Prepare a gap in an electrical circuit. For this purpose disconnect one of the feeding wires from the entrance switch. On its place attach a necessary piece of a wire, previously having smoothed out the ends at necessary length. Prepare two pieces of a wire of necessary length. Length of all wires is selected, proceeding from arrangement of electric equipment and the measuring device.
2. Direct method of measurement of power. Attach a wattmeter to an electrical circuit. Connect the channel of current in in advance prepared gap. Attach the channel of tension by means of additional wires to the entrance switch. Give tension, by turning on of the automatic machine or the switch. On the indicator of the device determine the size of power consumption.
3. Indirect method of measurement. Attach a multimeter in the prepared rupture of an electrical circuit. Transfer the device to the mode of measurement of current. Give tension by turning on of the automatic switch. Read out indications of current from the indicator of the device and remember or write down them. Disconnect tension. Disconnect a multimeter and restore an electrical circuit in the form in which it was prior to measurements. Give tension. Transfer a multimeter to the voltage measurement mode. Make measurement of value of supply voltage by touch by device probes to output terminals of the switch. Also remember the received value of tension or write down. Calculate power consumption, having multiplied the measured value of current on value of tension. If current was measured in amperes, and tension in volts, the received size will have dimension – Watt (W).